Logan sapphire

  The Logan sapphire is named after Mrs. John Logan who donated the gemstone to the Smithsonian Institute in 1960. The Logan sapphire is a flawless specimen, possesses a rich blue color and is the second largest (blue) sapphire known, weighing 423 carats (84.6 g). The cushion-cut stone is one of the world's most famous sapphires and is set in a brooch surrounded by 20 round brilliant cut diamonds weighing in total 16 carats (3.2 g). The Logan sapphire originates from Sri Lanka, a famous location for sapphires.

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